AVC / H.264 Encoder (Push)
Contents
AVC / H.264 Encoder (Push)#
This article explains how you can use Transcoder::push to encode an AVC / H.264 elementary stream from raw YUV frames.
Source Video#
As video input we use the foreman_qcif.yuv file from the AVBlocks Assets archive. After downloading and unzipping you will find foreman_qcif.h264 in the vid subdirectory.
Code#
This code shows how you can encode raw uncompressed YUV frames into an H.264 stream. Two Transcoder objects are used, one to read the raw YUV frames from a file, and another to encode the raw frames to AVC / H.264 Annex B stream. The encoding is done via the Transcoder::push method.
Windows#
Initialize AVBlocks#
void encode_h264_stream()
{
Library::initialize();
encode_h264_stream(L"foreman_qcif.yuv", L"foreman_qcif.h264");
Library::shutdown();
}
Configure YUV Reader Transcoder#
p::ref<Transcoder> create_yuv_reader(const char_t* inputFile)
{
// Create VideoStreamInfo, MediaPin, and MediaSocket describing the YUV input
// VideoStreamInfo
p::ref<VideoStreamInfo> yuvInVideo(Library::createVideoStreamInfo());
yuvInVideo->setStreamType(StreamType::UncompressedVideo);
yuvInVideo->setFrameRate(30.0);
yuvInVideo->setFrameWidth(176);
yuvInVideo->setFrameHeight(144);
yuvInVideo->setColorFormat(ColorFormat::YUV420);
yuvInVideo->setScanType(ScanType::Progressive);
// MediaPin
p::ref<MediaPin> yuvInPin(Library::createMediaPin());
yuvInPin->setStreamInfo(yuvInVideo.get());
// MediaSocket
p::ref<MediaSocket> yuvInSocket(Library::createMediaSocket());
yuvInSocket->setStreamType(StreamType::UncompressedVideo);
yuvInSocket->setFile(inputFile);
yuvInSocket->pins()->add(yuvInPin.get());
// Create VideoStreamInfo, MediaPin, and MediaSocket describing the YUV output
// This is the same as the input, but no output file is set on the MediaSocket,
// because we want to pull frames one by one using Transcoder::pull
// VideoStreamInfo
p::ref<VideoStreamInfo> yuvOutVideo(Library::createVideoStreamInfo());
yuvOutVideo->setStreamType(StreamType::UncompressedVideo);
yuvOutVideo->setFrameRate(30.0);
yuvOutVideo->setFrameWidth(176);
yuvOutVideo->setFrameHeight(144);
yuvOutVideo->setColorFormat(ColorFormat::YUV420);
yuvOutVideo->setScanType(ScanType::Progressive);
// MediaPin
p::ref<MediaPin> yuvOutPin(Library::createMediaPin());
yuvOutPin->setStreamInfo(yuvOutVideo.get());
// MediaSocket
p::ref<MediaSocket> yuvOutSocket(Library::createMediaSocket());
yuvOutSocket->setStreamType(StreamType::UncompressedVideo);
yuvOutSocket->pins()->add(yuvOutPin.get());
// Create Transcoder
p::ref<Transcoder> yuvReader(Library::createTranscoder());
yuvReader->inputs()->add(yuvInSocket.get());
yuvReader->outputs()->add(yuvOutSocket.get());
return yuvReader;
}
Configure AVC / H.264 Encoder Transcoder#
p::ref<Transcoder> create_h264_encoder(const char_t* outputFile, HardwareEncoder::Enum hardware)
{
// Create VideoStreamInfo, MediaPin, and MediaSocket describing the YUV input
// VideoStreamInfo
p::ref<VideoStreamInfo> yuvInVideo(Library::createVideoStreamInfo());
yuvInVideo->setStreamType(StreamType::UncompressedVideo);
yuvInVideo->setFrameRate(30.0);
yuvInVideo->setFrameWidth(176);
yuvInVideo->setFrameHeight(144);
yuvInVideo->setColorFormat(ColorFormat::YUV420);
yuvInVideo->setScanType(ScanType::Progressive);
// MediaPin
p::ref<MediaPin> yuvInPin(Library::createMediaPin());
yuvInPin->setStreamInfo(yuvInVideo.get());
// MediaSocket
p::ref<MediaSocket> yuvInSocket(Library::createMediaSocket());
yuvInSocket->setStreamType(StreamType::UncompressedVideo);
yuvInSocket->pins()->add(yuvInPin.get());
// Create VideoStreamInfo, MediaPin, and MediaSocket describing the H.264 output
// VideoStreamInfo
p::ref<VideoStreamInfo> h264OutVideo(Library::createVideoStreamInfo());
h264OutVideo->setStreamType(StreamType::H264);
h264OutVideo->setFrameRate(30.0);
h264OutVideo->setFrameWidth(176);
h264OutVideo->setFrameHeight(144);
h264OutVideo->setColorFormat(ColorFormat::YUV420);
h264OutVideo->setScanType(ScanType::Progressive);
// MediaPin
p::ref<MediaPin> h264OutPin(Library::createMediaPin());
h264OutPin->setStreamInfo(h264OutVideo.get());
// Enable \ disable hardware acceleration
h264OutPin->params()->addInt(Param::HardwareEncoder, hardware);
// MediaSocket
p::ref<MediaSocket> h264OutSocket(Library::createMediaSocket());
h264OutSocket->setStreamType(StreamType::H264);
h264OutSocket->setFile(outputFile);
h264OutSocket->pins()->add(h264OutPin.get());
// Transcoder
p::ref<Transcoder> h264Encoder(Library::createTranscoder());
h264Encoder->inputs()->add(yuvInSocket.get());
h264Encoder->outputs()->add(h264OutSocket.get());
return h264Encoder;
}
Open Transcoders#
void encode_h264_stream(const char_t* inputFile, const char_t* outputFile)
{
// Create a reader to simulate raw video frames. In reality you will likely
// have a different raw video source, for example some kind of video capture device.
p::ref<Transcoder> yuvReader = create_yuv_reader(inputFile);
// Create a H.264 encoder. We will pass the raw video frames to it to encode them as H.264
p::ref<Transcoder> h264Encoder = create_h264_encoder(outputFile, HardwareEncoder::Auto);
if (yuvReader->open())
{
if (h264Encoder->open())
{
encode_h264_stream(yuvReader.get(), h264Encoder.get());
h264Encoder->close();
}
yuvReader->close();
}
}
Call Transcoder::pull and Transcoder::push#
void encode_h264_stream(Transcoder* yuvReader, Transcoder* h264Encoder)
{
int32_t inputIndex = 0;
p::ref<MediaSample> yuvFrame(Library::createMediaSample());
while (true)
{
// Simulate a raw frame
// Each call to Transcoder::pull returns one video frame.
if (!yuvReader->pull(inputIndex, yuvFrame.get()))
break;
// Pass the raw video frame to Transcoder::push to encode it as AVC / H.264
if (!h264Encoder->push(0, yuvFrame.get()))
break;
}
h264Encoder->flush();
}
Complete C++ Code#
#include <primo/avblocks/avb.h>
#include <primo/platform/reference++.h>
// link with AVBlocks64.lib
#pragma comment(lib, "./avblocks/lib/x64/AVBlocks64.lib")
namespace p = primo;
using namespace p::codecs;
using namespace p::avblocks;
p::ref<Transcoder> create_yuv_reader(const char_t* inputFile)
{
// Create VideoStreamInfo, MediaPin, and MediaSocket describing the YUV input
// VideoStreamInfo
p::ref<VideoStreamInfo> yuvInVideo(Library::createVideoStreamInfo());
yuvInVideo->setStreamType(StreamType::UncompressedVideo);
yuvInVideo->setFrameRate(30.0);
yuvInVideo->setFrameWidth(176);
yuvInVideo->setFrameHeight(144);
yuvInVideo->setColorFormat(ColorFormat::YUV420);
yuvInVideo->setScanType(ScanType::Progressive);
// MediaPin
p::ref<MediaPin> yuvInPin(Library::createMediaPin());
yuvInPin->setStreamInfo(yuvInVideo.get());
// MediaSocket
p::ref<MediaSocket> yuvInSocket(Library::createMediaSocket());
yuvInSocket->setStreamType(StreamType::UncompressedVideo);
yuvInSocket->setFile(inputFile);
yuvInSocket->pins()->add(yuvInPin.get());
// Create VideoStreamInfo, MediaPin, and MediaSocket describing the YUV output
// This is the same as the input, but no output file is set on the MediaSocket,
// because we want to pull frames one by one using Transcoder::pull
// VideoStreamInfo
p::ref<VideoStreamInfo> yuvOutVideo(Library::createVideoStreamInfo());
yuvOutVideo->setStreamType(StreamType::UncompressedVideo);
yuvOutVideo->setFrameRate(30.0);
yuvOutVideo->setFrameWidth(176);
yuvOutVideo->setFrameHeight(144);
yuvOutVideo->setColorFormat(ColorFormat::YUV420);
yuvOutVideo->setScanType(ScanType::Progressive);
// MediaPin
p::ref<MediaPin> yuvOutPin(Library::createMediaPin());
yuvOutPin->setStreamInfo(yuvOutVideo.get());
// MediaSocket
p::ref<MediaSocket> yuvOutSocket(Library::createMediaSocket());
yuvOutSocket->setStreamType(StreamType::UncompressedVideo);
yuvOutSocket->pins()->add(yuvOutPin.get());
// Create Transcoder
p::ref<Transcoder> yuvReader(Library::createTranscoder());
yuvReader->inputs()->add(yuvInSocket.get());
yuvReader->outputs()->add(yuvOutSocket.get());
return yuvReader;
}
p::ref<Transcoder> create_h264_encoder(const char_t* outputFile, HardwareEncoder::Enum hardware)
{
// Create VideoStreamInfo, MediaPin, and MediaSocket describing the YUV input
// VideoStreamInfo
p::ref<VideoStreamInfo> yuvInVideo(Library::createVideoStreamInfo());
yuvInVideo->setStreamType(StreamType::UncompressedVideo);
yuvInVideo->setFrameRate(30.0);
yuvInVideo->setFrameWidth(176);
yuvInVideo->setFrameHeight(144);
yuvInVideo->setColorFormat(ColorFormat::YUV420);
yuvInVideo->setScanType(ScanType::Progressive);
// MediaPin
p::ref<MediaPin> yuvInPin(Library::createMediaPin());
yuvInPin->setStreamInfo(yuvInVideo.get());
// MediaSocket
p::ref<MediaSocket> yuvInSocket(Library::createMediaSocket());
yuvInSocket->setStreamType(StreamType::UncompressedVideo);
yuvInSocket->pins()->add(yuvInPin.get());
// Create VideoStreamInfo, MediaPin, and MediaSocket describing the H.264 output
// VideoStreamInfo
p::ref<VideoStreamInfo> h264OutVideo(Library::createVideoStreamInfo());
h264OutVideo->setStreamType(StreamType::H264);
h264OutVideo->setFrameRate(30.0);
h264OutVideo->setFrameWidth(176);
h264OutVideo->setFrameHeight(144);
h264OutVideo->setColorFormat(ColorFormat::YUV420);
h264OutVideo->setScanType(ScanType::Progressive);
// MediaPin
p::ref<MediaPin> h264OutPin(Library::createMediaPin());
h264OutPin->setStreamInfo(h264OutVideo.get());
// Enable \ disable hardware acceleration
h264OutPin->params()->addInt(Param::HardwareEncoder, hardware);
// MediaSocket
p::ref<MediaSocket> h264OutSocket(Library::createMediaSocket());
h264OutSocket->setStreamType(StreamType::H264);
h264OutSocket->setFile(outputFile);
h264OutSocket->pins()->add(h264OutPin.get());
// Transcoder
p::ref<Transcoder> h264Encoder(Library::createTranscoder());
h264Encoder->inputs()->add(yuvInSocket.get());
h264Encoder->outputs()->add(h264OutSocket.get());
return h264Encoder;
}
void encode_h264_stream(Transcoder* yuvReader, Transcoder* h264Encoder)
{
int32_t inputIndex = 0;
p::ref<MediaSample> yuvFrame(Library::createMediaSample());
while (true)
{
// Simulate a raw frame
// Each call to Transcoder::pull returns one video frame.
if (!yuvReader->pull(inputIndex, yuvFrame.get()))
break;
// Pass the raw video frame to Transcoder::push to encode it as AVC / H.264
if (!h264Encoder->push(0, yuvFrame.get()))
break;
}
h264Encoder->flush();
}
void encode_h264_stream(const char_t* inputFile, const char_t* outputFile)
{
// Create a reader to simulate raw video frames. In reality you will likely
// have a different raw video source like for example some kind of video capture device.
p::ref<Transcoder> yuvReader = create_yuv_reader(inputFile);
// Create a H.264 encoder. We will pass the raw video frames to it to encode them as H.264
p::ref<Transcoder> h264Encoder = create_h264_encoder(outputFile, HardwareEncoder::Auto);
if (yuvReader->open())
{
if (h264Encoder->open())
{
encode_h264_stream(yuvReader.get(), h264Encoder.get());
h264Encoder->close();
}
yuvReader->close();
}
}
void encode_h264_stream()
{
Library::initialize();
encode_h264_stream(L"foreman_qcif.yuv", L"foreman_qcif.h264");
Library::shutdown();
}
int main(int argc, const char * argv[]) {
encode_h264_stream();
return 0;
}
How to run#
Create a C++ console application in Visual Studio and use the code from this article.
Copy the foreman_qcif.yuv file from the assets archive to x64/Debug under the project’s directory.
Run the application in Visual Studio.